Place butter in large bowl of a stand mixer. Using the whisk attachment, mix on high speed until it becomes light and fluffy. This will take about 5 minutes.

While mixing the butter, place whole Oreos in a food processor and process until a fine texture is reached. Set aside.

Turn mixer to low speed and switch to paddle attachment, add vanilla, pinch of salt if needed, and 1 cup of icing sugar. Add in 1 tbsp of cream. Once icing sugar is mostly mixed in, increase speed and mix until all the icing sugar in incorporated.

Add another cup of icing sugar followed by a tablespoon of cream and repeat until all the icing sugar is mixed in evenly, adding enough cream until desired consistency is reached. Scrape down the sides of the bowl in between.

Add in crushed Oreos and mix on low-medium setting until evenly distributed.

If using a piping bag with tip, be sure to use large open tips. If not using right away, cover the bowl with plastic wrap as this buttercream will set and become firm quickly!